Microbial adhesion onto biomaterial implants and the subsequent formation of biofilms are one of the major reasons for failure of implantable biomedical devices, and about 45% of nosocomial infections are caused by biomaterial-associated infections. These nosocomial microbial infections associated with implanted biomedical devices such as implantable sensors, catheters and artificial prosthetics, typically lead to removal of the devices due to the lack of a suitable treatment, and increase the duration of hospital stays and hospitalization costs. Currently, there is a constant demand for new materials capable of preventing the colonization of microorganisms onto surfaces of implantable materials.
To reduce bacterial attachment and colonization, one method is to coat surfaces with nonfouling materials such as poly(ethylene glycol) (PEG) derivatives or zwitterionic polymers. Surfaces coated with 2-methacryloyloxyethyl phosphorylcholine (MPC) reduce the attachment of bacteria by 90%. Recent studies demonstrated that zwitterionic poly(sulfobetaine methacrylate) (pSBMA) and poly(2-carboxy-N,N-dimethyl-N-(2′-(methacryloyloxy)ethyl)ethanaminium) (pCBMA-2) efficiently reduced the colonization of Pseudomonas aeruginosa and Staphylococcus epidermidis. These materials are also proved to be highly resistant to protein adsorption from 100% serum and blood plasma. Although these non-fouling materials can significantly reduce the initial attachment and delay the colonization of microbes on the surfaces, they cannot kill or inhibit the growth of pathogenic bacteria cells once bacteria are attached to surfaces.
During implantation surgery, there is a great possibility of introducing pathogenic microbes into the patient, thereby causing the failure of implantation devices. The antimicrobial strategy is another method for preventing bacterial colonization on surfaces. Quaternary ammonium compounds (QACs) are extensively used as antimicrobial agents due to their broad antimicrobial properties. These QACs, when covalently linked to material surfaces to make the surface permanent microbiocidal, are able to efficiently kill both bacterial cells and fungal cells. However, permanent QACs coatings cannot fulfill the requirement of implantable biomaterials for non-fouling and biocompatibility. The inherent drawback of permanent QAC coatings is that they generate a fouling surface that triggers the immune response and chronic inflammation.
Despite the advances noted above, a need exists for a multi-functional polymers and that combines the advantages of non-fouling and cationic antimicrobial materials, while overcoming their respective disadvantages. The present invention seeks to fulfill this need and provides further related advantages.